Wind deflectors for attachment to the main bracket of a wiper blade are already known.
EP 0 398 376 A1 shows a wind deflector that can be fastened to the main bracket of a wiper blade with a total of two fastening sections. The main bracket is designed to be essentially u-shaped in cross-section and has a spine from which two side walls extend downward in the direction of the windshield that is to be cleaned. In the spine of the main bracket are openings that do not directly reach to the side walls. The fastening of the wind deflector is accomplished with each of the two fastening sections in the area of one of the openings in the spine of the main bracket, whereby the fastening sections are mounted from above on the spine of the main bracket. One of the fastening sections is designed so that a protruding section of it engages from behind with the edge of the opening in the main bracket spine. The second fastening section lies above on the edge of an opening, and a molded part is inserted from below into the main bracket, whereby the portions of the fastening section and the molded part that are arranged on both sides of the opening are screwed together by means of a fastening screw.
In the case of such a fastening, the possibility exists that under the action of the corresponding force from the stream of air that hits the wind deflector, the wind deflector may move relative to the main bracket. As a result, the flow conditions may be unintentionally affected negatively. In contrast, it may be that the fastening of the unscrewed fastening section may release unintentionally. In addition, fastening with only two fastening points for extended wind deflectors does not appear to be appropriate. In the case of EP 0 398 376 A1, the wind deflector is shorter than the main bracket and thus considerably shorter than the supporting frame of the wiper blade. As a result, the increase that can be achieved in the force with which the wiper blade is pressed against the windshield is correspondingly small. In addition, the installation of the wind deflector on the wiper blade is somewhat expensive since the wind deflector as well as the molded part and the fastening screw must be handled individually at the same time, whereby they have to be brought into the installation position and then held in place until final installation.
From EP 0 433 169 A1, another wind deflector is known that is manufactured from plastic for a wiper blade with a main bracket that is essentially u-shaped in cross-section. This wind deflector, which is somewhat longer than the main bracket but considerably shorter than the supporting frame of the wiper blade, is to be fastened to the main bracket with two relatively narrow fastening sections. To this end, the two fastening sections are matched in cross-section in like fashion to the cross-section of the main bracket and provided on both U-legs with catching projections which in each case can engage under a lower edge of a side wall of the main bracket. This wind deflector is thus fastened in an advantageously simple manner by just locking onto the main bracket on the wiper blade. A defect in turn consists in that the wind deflector may move on the wiper blade or else there may be an unintentional release of one or both catch connections. It is also clear to one skilled in the art that, owing to considerations of materials processing or machine-tool engineering, the production of the inward-facing catching projections on the U-legs of the fastening sections requires that in each case a slot-like opening be made in the spine of each fastening section. In the corresponding form tool, an additional slide that can make these openings in the spine of the fastening section must be used in each case for the undercuts of the catching projection. These openings in turn greatly weaken the basic cross-section of the spine of the fastening section, so that the risk of rupture exists at this point when there is stress. The necessary stability and strength of the combination of wind deflector and wiper blade cannot be ensured.
The object of the invention is to further develop a wind deflector of the type mentioned above, in such a way that both in the initial installation and in the retrofitting of suitable wiper blades, sufficient strength or stability both of the fastening section of the wind deflector and of the combination of wind deflector and wiper blade is ensured.